This invention relates to toolholders and is especially concerned with toolholders with a body having an insert seat on one end and a shank receivable in the bore of the tool support member on the other end. Such tools are used in the cutting and shaping of rotating workpieces where it is important that the toolholder be held in a rigid manner so that no movement occurs during the metal cutting operation.
Many devices in the prior art have proved to to be successful in this regard. In 1970, McCreery was granted U.S. Pat. No. 3,498,653 for his invention on a connector device for a toolholder having an insert seat thereon and a shank receivable in a bore of a toolholder. Since then, other patents having been granted to McCray et al (U.S. Pat. No. 4,135,418) and Bator (U.S. Pat. No. 251,971). The above devices are concerned with the use of ball-like elements to hold the shank of the toolholder in the bore of the tool support member.
Other types of toolholders are firmly anchored to the tool support member, and rather than change the entire toolholder, the insert on the toolholder itself is changed. The number of devices and ways that the cutting insert itself may be held are too numerous to mention in this specification. One of the many ways, however, was described by Friedline et al in U.S. Pat. No. 3,953,143, which comprises an expansible plug member that was loosely receivable in a blind hole and, when expanded, would clamp a cutting insert against a wall of the blind hole. Many other ways of holding a cutting insert in an insert seat of a toolholder have been described by Friedline and others, however.
A need for a faster, more reliable means of interchanging inserts and toolholders is always present, and for this reason, improvements in tool-holders are always being sought.